Measuring of Object through Image Processing

I want to measure object's length through image processing in accuracy of 0.001mm. means 1 pixel = 0.001mm, than how much zooming i need and i have doubt that that much accuracy or zooming is possible? if possible开发者_运维知识库 than is there any camera which can give me that much accuracy?

It all depends on the lens and sensor on the camera. Digital cameras on microsopes can be this accurate. You can test it against a known size and see if you've got the accuracy, and also scale the distance. The distance of the object from the lens will have to be constant or adjusted for in the program.